System and method for providing tempered fluid

ABSTRACT

The present invention is directed to methods and apparatus for tempering the temperature of a liquid in a fluid conducting system. More particularly, some embodiments of the invention relates to tempering the temperature of water supplied to a fixture from a water heater in a fluid conducting system. The system can include a heater for heating the fluid and a diffuser for slowing the rate at which water provided to a decontamination fixture is heated.

This application is a continuation of U.S. patent application Ser. No.13/213,811, filed Aug. 19, 2011, now issued as U.S. Pat. No. 8,595,869,which is a continuation of U.S. patent application Ser. No. 12/687,327,filed Jan. 14, 2010, now issued as U.S. Pat. No. 8,001,628, which is adivisional of U.S. patent application Ser. No. 11/180,380, filed Jul.13, 2005, now issued as U.S. Pat. No. 7,657,950, which claims priorityto U.S. Provisional Application No. 60/592,710, filed Jul. 30, 2004,herein incorporated by reference in its entirety.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention concerns a method and apparatus for tempering thetemperature of a liquid in a fluid conducting system. More particularly,the invention relates to tempering the temperature of water supplied toa fixture from a water heater in a fluid conducting system.

Thermally controlled or thermostatic mixing valves are well known.Valves of this type receive both hot and cold fluid, typically water,and allow the fluids to mix to an intermediate temperature. Thetemperature is controlled using a thermally responsive control member,such as a thermostat, to assist in maintaining the fluid temperatureaccording to an established setting.

One particular application of thermostatic mixing valves is inconnection with emergency shower and eyewash systems. Toxic andhazardous chemicals are used in many environments, whether inside afactory building or outside at a remote construction site. TheOccupational Safety and Health Act of 1970 was enacted to assure thatworkers would be provided with safe and healthful working conditions.Pursuant to this act, the Occupational Safety and Health Administrationadopted regulations which require the availability of emergency eyewashand shower equipment for use as a form of first aid treatment. Emergencyshower and eyewash systems have proliferated in a wide range ofindustries, including automotive, food processing, chemical processing,petroleum refining, steel production, pulp and paper, and waste watertreatment. In each of these industries, workers may be exposed tochemicals that may cause serious tissue damage and destruction. Theseemergency shower and eyewash facilities are commonly associated withpermanent structures and may be located inside or outside factorybuildings with access to hot and cold water.

In emergency fixture systems such as eyewash and emergency showersystems, even ground water of a moderate temperature (such as in therange of 50 degrees to 60 degrees F., as is common) is often perceivedto be too cold, possibly discouraging sufficient duration of use of theemergency equipment. In addition, in northern climates, the ground wateritself is sometimes barely above freezing, commonly near 35 degrees F.Under these circumstances, an emergency shower and eyewash systemrelying solely upon ground water often provides water that would be toocold to be endured for a sufficient period of time, even by a victim ofa chemical accident.

As a result, emergency shower and eyewash systems have been designed toprovide tempered water by blending relatively hotter water withrelatively colder water. A range of temperatures between 65 degrees F.to 95 degrees F. is comfortable to most persons. To provide temperedwater within this range, most emergency fixture systems include a sourceof hot water, typically in the range of 140 degrees F. to 160 degreesF., that is mixed with ambient ground water.

Many outdoor or other remote worksites such as construction sites mayhave the same or similar hazards that are associated with indoorworksites. Such remote worksites typically do not have a ready supply ofhot water. Thus, workers at such sites exposed to chemicals or otherirritants typically do not have access to emergency fixture systems thatprovide an adequate supply of tempered fluid, properly directed, for asufficient period of time. Such workers may be required to resort to aground-temperature water supply from a garden hose, a squirt bottle eyerinse apparatus, or other less suitable sources of fluid to rinse theexposed area(s).

Emergency shower and eyewash systems must typically drench or rinse auser for at least 15 minutes. Thus, the source of tempered water shouldbe able to provide the water for at least that length of time and tomaintain the water within a comfortable temperature range for the user.In addition, the system should be able to maintain tempering of thewater regardless of extreme fluctuations in the supply of hot or coldwater to the thermostatic mixing valve. Often, a thermostatic mixingvalve is used to maintain the water at an appropriately temperedtemperature.

The valve should respond accordingly to failures in the supply of hot orcold water to the valve, as well as failure of the valve itself. Thevalve should respond to these failures without placing the user of theemergency shower or eyewash system in greater peril than the user wouldbe without the emergency system. For example, if the cold water supplyfails and only hot water in the range of 140 degrees F. to 160 degreesF. is supplied, the user could suffer burns that may be more seriousthan the exposure being treated. Thus, it is desirable for the valve toprevent or minimize exposure to such hot water.

Thermostatic mixing valves typically include a housing including hot andcold inlets, a mixed fluid outlet, a valve control assembly to adjustthe amounts of hot and/or cold fluid permitted to flow through thevalve, and a thermostat to control movement of the control assembly. Thethermostat is typically positioned at least partially in the housing tosense the temperature of the mixture of fluid therein. The thermostatincludes a material that is responsive to changes in the fluidtemperature. For example, if the temperature increases, then movement ofthe thermostat causes movement of the control assembly, eitherincreasing the flow of cold fluid, decreasing the flow of hot fluid, orboth.

Frequently, some fluid in the fluid circulation system of which thethermostatic mixing valve is a part has been stagnant for a period oftime. During this stagnancy, the temperature of the hot fluid in the hotfluid supply line approaches ambient temperature, usually lower than thetemperature of the hot fluid from the hot fluid supply. In a typicalthermostatic mixing valve, when the temperature of the mixed fluidsensed by the thermostat is below the set point, the thermostatcooperates with the valve control assembly to increase the flow of hotfluid relative to the flow of cold fluid.

In such a stagnant fluid circulation system, when a fixture (such as aneyewash station) is eventually actuated, the thermostat is often exposedto mixed water at a temperature below the set point temperature, even ifthe ratio of water from the hot and cold fluid supplies otherwise wouldbe proportioned (if the hot fluid were at temperature) to produce mixedfluid at the desired temperature. Accordingly, responsive changes in thethermostat cause the valve control assembly to move to a position thatincreases the flow of hot fluid relative to the flow of cold fluid, thusincreasing the mixed fluid temperature. As the valve continues toreceive the supply of fluid from the hot fluid supply line that wasformerly stagnant, the thermostat continues to cause the valve controlassembly to move to a position that further increases flow from the hotfluid supply line and/or decreases the flow of cold fluid. If asufficient volume of stagnant fluid is in the supply line between thehot fluid supply and the mixing valve, this process may continue untilthe thermostat has caused the valve assembly to move to a positionwide-open to maximize the flow of fluid from the hot fluid source.

Eventually, hot fluid from in the hot fluid supply (such as a waterheater) progresses to the mixing valve. Because the valve controlassembly is now wide-open to the hot fluid inlet, a large volume of hotfluid enters the valve housing through the hot fluid supply line thathad previously been the source of the stagnant (and cooler) fluid. Oncethe hot fluid reaches the thermostat after mixing with whatever coldfluid is entering the valve, the thermostat responds to the temperatureincrease, causing the valve control assembly to move to reduce the flowof hot fluid and/or increase the flow of cold fluid. The length of timefor the thermostat to respond as such and move the valve controlassembly by a sufficient amount to reduce the temperature of mixed fluidbelow the set point can be long enough to permit a quantity of waterabove the set point temperature to flow from the valve.

Thus, in one aspect of the invention, a decontamination apparatus isprovided, comprising a fluid supply inlet configured for coupling to afluid supply source, a first fluid line coupled to the fluid supplyinlet and formed to include a first passageway in which a first fluidflows, and a heat exchange assembly configured to heat the first fluidin the first fluid line. The apparatus also comprises a mixing valveincluding a valve body formed to include a first fluid inlet to receivethe first fluid from the first fluid line, a second fluid inlet toreceive a second fluid from a second fluid line, and a mixed fluidoutlet. A decontamination fixture is coupled to the mixed fluid outletconfigured to discharge the mixed fluid. Optionally, a supportinterconnects at least the heat exchange assembly, the first fluid line,the mixing valve, and the decontamination fixture to permit movement ofthe apparatus as a unit.

In one illustrative example according to this aspect of the invention,the support is a frame including frame members coupled together, aplatform coupled to the frame, and wheels coupled to the frame tofacilitate movement of the decontamination apparatus.

In another illustrative example according to this aspect of theinvention, the support includes a platform having a structure includinga generally upwardly facing surface on which the heat exchange assembly,mixing valve, and decontamination fixture are supported, and a pluralityof spaced apart support members coupled to and extending downwardly fromthe structure.

Illustratively according to this aspect of the invention, the first andsecond fluid lines comprise fluid provided by the fluid supply source.

Additionally illustratively according to this aspect of the inventionthe apparatus further comprises a junction in fluid communication withthe fluid supply inlet, the junction splitting flow of fluid from thefluid supply source into the first fluid line and the second fluid line.

Illustratively according to this aspect of the invention the secondfluid line configured to be coupled to a second fluid supply source andformed to include a second passageway in which a second fluid streamflows.

Illustratively according to this aspect of the invention the heatexchange assembly comprises a burner configured to combust fuel from afuel source, and at least a portion of the first fluid passageway isproximate the burner so that when fuel from the fuel source is combustedat the burner, heat from the combustion is transferred into the firstfluid in the first fluid passageway.

Additionally illustratively according to this aspect of the invention,the burner is coupled to a controller, the decontamination fixtureincludes an actuator to actuate a valve controlling flow of fluid fromthe decontamination fixture, the burner igniting upon actuation of thedecontamination fixture by a signal sent by the controller.

Additionally illustratively according to this aspect of the inventionthe apparatus further comprises a fuel tank in which the fuel is stored,the fuel tank coupled to the frame to enable movement of the fuel tankupon movement of the frame.

Illustratively according to this aspect of the invention the apparatusfurther comprises wheels coupled to the frame to facilitate movement ofthe decontamination apparatus.

Additionally illustratively according to this aspect of the inventionthe apparatus further comprises a stand coupled to the frame tocooperate with the wheels to maintain decontamination apparatus in aposition suitable for use by a user.

Illustratively according to this aspect of the invention, the apparatusfurther comprises a means for dampening temperature change of the firstfluid prior to entry into the first fluid inlet of the thermostaticmixing valve so that the mixing valve can adjust to a particulartemperature increase over a given time period.

Illustratively according to this aspect of the invention, the apparatusfurther comprises a diffuser coupled between the hot fluid line and thehot inlet to the mixing valve, the diffuser including a first fluidconduit and at least a second fluid conduit, a majority of the firstfluid conduit being surrounded by the second fluid conduit, the firstand second conduits being coupled together to cause fluid to flow intothe first conduit, pass through a plurality of apertures formed in thefirst conduit, and into fluid outside the first conduit and in thesecond conduit.

Illustratively according to this aspect of the invention, thedecontamination fixture is an eyewash fixture including a basin and atleast one nozzle directed at least partially upwardly.

Illustratively according to this aspect of the invention, thedecontamination fixture is a drench shower having fluid outlets directedat least partially downwardly.

Illustratively according to this aspect of the invention, thedecontamination fixture is a wand including a trigger configured to beactuated by a user and a spray nozzle to direct the flow of fluid fromthe wand depending on a direction selected by a user.

According to another aspect of the invention, an apparatus forincreasing the time period over which a temperature change occurs at apoint in a fluid conducting system having fluid flowing therethroughcomprises a first conduit having first and second ends and a pluralityof openings provided between the first and second ends, a second conduithaving first and second ends, the second conduit being coupled to thefirst conduit and at least partially surrounding at least a portion ofthe first conduit, wherein at least one of the openings is in theportion of the first conduit surrounded by the second conduit, one ofthe second conduit and the first conduit including a fluid inlet, andthe other of the second conduit and the first conduit including a fluidoutlet, wherein the first and second conduits are arranged to permitfluid to flow from the inlet to the outlet.

Illustratively according to this aspect of the invention, the secondconduit and the first conduit are connected together to permit fluid toflow from the fluid inlet toward the fluid outlet.

Additionally illustratively according to this aspect of the invention,the first conduit and the second conduit are coupled together by a unionthat seals a first end of each of the first and second conduit so thatfluid is inhibited from passing from the first end of the first conduitinto the region between the first and second conduits adjacent the firstend of the first conduit.

Further illustratively according to this aspect of the invention, asecond end of the second conduit is sealed with a cap to prevent fluidfrom flowing out of the second end of the second conduit.

Further illustratively according to this aspect of the invention, asecond end of the first conduit is spaced apart from the cap to permitfluid to flow from the second end of the first conduit adjacent the cap,and into the region between the first and second conduits.

Additionally illustratively according to this aspect of the invention,the union is formed to include an outlet to permit fluid to flow fromthe first end of the second conduit out of the outlet.

Further illustratively according to this aspect of the invention, theunion includes a first end having an opening sized to receive the firstend of the second conduit, and the union includes a second end having anopening sized to receive the first end of the first conduit.

Further illustratively according to this aspect of the invention, thefirst and second ends of the union are separated by a generallyfrustoconical reducing region.

Illustratively according to this aspect of the invention, the first andsecond fluid conduits are coupled so that fluid flowing within the firstconduit flows substantially in the opposite direction as fluid flowingwithin the second conduit.

Additionally illustratively according to this aspect of the invention,the apparatus further comprises a third fluid conduit, wherein at leasta portion of the first fluid conduit is surrounded by the second andthird fluid conduits, and at least a portion of the second fluid conduitis surrounded by the third fluid conduit.

Further illustratively according to this aspect of the invention, thefluid flowing through and immediately adjacent to the first and thirdfluid conduits flows in a direction substantially parallel within eachconduit.

Illustratively according to this aspect of the invention, the apparatusfurther comprises a plurality of apertures in the second fluid conduitcomprise a first aperture, a second aperture, and a third aperture, thefirst aperture being spaced from the second aperture by a firstdistance, and the second aperture being spaced from the third aperture asecond distance, the first distance being greater than the second.

Illustratively according to this aspect of the invention, the first andsecond fluid conduits define a void having a volume capable of receivingat least 0.13 gallons of fluid.

Additionally illustratively according to this aspect of the invention,the first, second and third conduits define a void having a volumecapable of receiving at least 0.9 gallons of fluid.

Illustratively according to this aspect of the invention, the pluralityof each of the apertures is substantially of one of the shapes selectedfrom the group consisting of: circular, square, rectangular,diamond-shaped, ovular, triangular, and irregular.

According to another aspect of the invention, a fluid mixing apparatusfor use in a fluid flow network comprises a mixing valve including ahousing having a hot fluid inlet, a cold fluid inlet, a mixed fluidoutlet, a mixing region, and a movable valve assembly to adjust therelative flow of fluid through the hot fluid inlet and the cold fluidinlet, and a first fluid conduit in fluid communication with the mixingvalve, the first fluid conduit including an inlet through which fluidflows from a hot fluid supply line and an outlet through which fluidflows toward the mixing valve, the first fluid conduit constructed toexpose fluid flowing through the inlet to a heat sink.

Illustratively according to this aspect of the invention, the heat sinkis a second fluid mass downstream of a first fluid mass. Additionallyillustratively according to this aspect of the invention, the apparatusfurther comprises a second fluid conduit coupled to the first fluidconduit, the first fluid conduit formed to include the inlet and formedto include a first conduit outlet through which fluid is capable offlowing out of the first fluid conduit and into the second fluidconduit. Further illustratively according to this aspect of theinvention, the apparatus further comprises a third conduit between thefirst and second fluid conduits. Additionally illustratively accordingto this aspect of the invention, the first fluid conduit has a length,and is formed to include a plurality of openings, at least one of theplurality of openings positioned between the ends of the first fluidconduit. Additionally illustratively according to this aspect of theinvention, a portion of the first fluid conduit is surrounded by thesecond fluid conduit. Additionally illustratively according to thisaspect of the invention, at least one of the first and second fluidconduits includes a plurality of fins extending from a surface of saidone of the first and second fluid conduits. Further illustrativelyaccording to this aspect of the invention, said one of the first andsecond fluid conduits is formed to include a plurality of apertures, atleast one of said plurality of apertures positioned between the ends ofthe fluid conduit including fins.

Illustratively according to this aspect of the invention, the heat sinkis a thermally conductive material having a mass per unit of linearlength of net fluid flow greater than the average mass per unit oflinear length of net fluid flow in the fluid flow network. Additionallyillustratively according to this aspect of the invention, the heat sinkcomprises copper.

Illustratively according to this aspect of the invention, the heat sinksurrounds the first conduit so that fluid flowing from the first fluidconduit subsequently flows through a passageway defined by the heatsink.

According to another aspect of the invention a decontamination apparatuscomprising a fluid heater, a cold fluid supply line, a hot fluid supplyline for supplying hot fluid from the fluid heater to a thermostaticmixing valve, the thermostatic mixing valve having a hot fluid inlet forreceiving fluid from to the hot fluid supply line, a cold fluid inletfor receiving fluid from the cold fluid supply line, and a mixed fluidoutlet for supplying fluid to a mixed fluid supply line through whichone, the other, or both of the hot and cold fluids flow from thethermostatic mixing valve, an emergency fixture connected to the mixedfluid supply line for supplying fluid therefrom to a user and configuredto deliver the mixed fluid at a flow rate and pattern to decontaminateeffectively at least a portion of the user's body, and a diffusercoupled between the hot fluid supply line and the thermostatic mixingvalve for increasing the time over which a temperature change isobserved at the hot fluid inlet.

In another aspect of the invention a decontamination apparatus comprisesa fluid supply inlet configured for coupling to a fluid supply source, acirculation network coupled to the fluid supply inlet and formed toinclude a first passageway in which a first fluid flows, a heater toheat the first fluid stream in the circulation network, adecontamination fixture connected to the circulation network to receiveheated fluid from the heater, and a support interconnecting at least theheater, fluid circulation network, and the decontamination fixture topermit movement of the apparatus as a unit.

Illustratively according to this aspect of the invention, the apparatusfurther comprises a mixing valve comprising a valve body formed toinclude a first fluid inlet to receive a first fluid from a first fluidline, a second fluid inlet to receive a second fluid from a second fluidline, and a mixed fluid outlet. Additionally illustratively according tothis aspect of the invention, the mixing valve further includes a valveassembly operably coupled to a thermostat to move the valve assembly toadjust the flow of at least one of the first and the second fluids tocontrol the mixed fluid temperature.

Additionally illustratively according to this aspect of the invention,the support is a pallet into which the tines of a fork truck can beinserted to lift and move the apparatus as a unit. Additionallyillustratively according to this aspect of the invention, the support isa frame having wheels coupled thereto so that a user can move theapparatus as a unit. Additionally illustratively according to thisaspect of the invention, the decontamination fixture includes a valveoperated by an actuator, and operation of the actuator causes fluid toflow from the circulation network through the mixing valve and throughthe decontamination fixture. Further illustratively according to thisaspect of the invention, operation of the actuator causes the heater toignite and heat the fluid flowing through the circulation network.

Additionally illustratively according to this aspect of the invention,the apparatus further comprises a diffuser positioned in the circulationnetwork to receive fluid from the heater, the diffuser configured toincrease the time over which a temperature increase is observed at theinlet of the fluid from the heater to the mixing valve.

Illustratively according to this aspect of the invention, the apparatusfurther comprises a fuel tank to store fuel usable by the heater togenerate heat for heating the fluid in the circulation network.Additionally illustratively according to this aspect of the invention,the support is a frame having wheels coupled thereto so that a user canmove the apparatus as a unit.

Additionally illustratively according to this aspect of the invention,the heater is configured to heat fluid on demand as the fluid flowsthrough the circulation network.

Illustratively according to this aspect of the invention, the heaterincludes a storage tank and is configured to heat fluid and store theheated fluid in the storage tank.

Additional features of the invention will become apparent to thoseskilled in the art upon consideration of the following detaileddescription of a preferred embodiment exemplifying the best mode ofcarrying out the invention as presently perceived.

BRIEF DESCRIPTION OF DRAWINGS

The detailed description particularly refers to the accompanying figuresin which:

FIG. 1 illustrates a decontamination apparatus for tempering fluid torinse substances from body parts of a victim, the apparatus having aheat exchange unit, fuel source, decontamination fixture, fluidcirculation network, diffuser, and mixing valve coupled with a supportto facilitate transportation of the decontamination apparatus;

FIG. 2 illustrates internal components of an illustrative heater for usewith the decontamination apparatus of FIG. 1;

FIG. 3 illustrates a decontamination apparatus for tempering fluidincluding a heat exchange unit, fluid circulation network,decontamination fixture, diffuser, and mixing valve positioned on asupport platform to facilitate transportation of the decontaminationapparatus;

FIG. 4 is a cross-sectional view of the diffuser shown in FIG. 1, takenalong line 4-4 thereof, showing the first and second conduitscooperating to form a two-pass diffuser;

FIG. 5 is a cross-sectional view of the diffuser shown in FIG. 3, takenalong line 5-5 thereof, showing the first, second, and third conduitscooperating to form a two-pass diffuser;

FIG. 6 is a perspective view of a decontamination fixture including adrench shower and an eyewash station;

FIG. 7 is a perspective view of a conduit for a diffuser having a spiralfin projecting away from the centerline through the conduit;

FIG. 8 is a cross-sectional view of a conduit for a diffuser having aplurality of holes formed therein;

FIG. 9 is a cross-sectional view of a conduit for a diffuser similar toFIG. 8 showing a hole having a diamond shape;

FIG. 10 is a cross-sectional view of a conduit for a diffuser similar toFIG. 8 showing a hole having an oval shape;

FIG. 11 is a cross-sectional view of a conduit for a diffuser similar toFIG. 8 showing a slot having a elongated rectangular shape;

FIG. 12 is a cross-sectional view of a conduit for a diffuser similar toFIG. 8 showing a hole having a trapezoidal shape;

FIG. 13 is a cross-sectional view of a conduit for a diffuser similar toFIG. 8 showing a plurality of circular holes spaced apart by varyingdistances;

FIG. 14 is a fragmentary view of a portion of the heater of FIG. 2,showing a pilot assembly with an igniter and a flame sensor;

FIG. 15 is a view of the pilot assembly of FIG. 14 showing a pilotflame;

FIG. 16 is a diagrammatic view of the heater of FIG. 2, showing acomputer connected to a gas proportioning valve, to a flow sensor thatis also coupled to the fluid inlet to the heater, and to a thermistorthat is also coupled to the hot fluid outlet line, the heat exchangerand a fuel inlet line;

FIG. 17 is a schematic view of the heater of FIG. 2 showing safetycircuitry including an overheat sensor, temperature limiter, and fluegas safety sensors and switches arranged in series and coupled to avalve to shut off flow of fuel upon detection of certain conditions;

FIG. 18 is a diagrammatic view of a decontamination apparatus includinga fluid supply, a heat exchanger receiving fluid from the fluid supplyand feeding heated fluid to a diffuser, the diffuser feeding fluid to amixing valve that, optionally, receives a supply of cold fluid from acold fluid source, and a mixed fluid stream flowing from the mixingvalve to an optional second diffuser then to an application;

FIGS. 19A through 190 are graphical data, also shown in tabular form inTable 1, of a test performed with a circulation system including hot andcold inlets, a diffuser similar to the diffuser of FIG. 5, and a mixedfluid outlet coupled to the diffuser, wherein —♦—represents cold water,—▪—represents hot water, —▴—represents mixed water temperature, and—x—represents water pressure; and

FIG. 20 is a diagrammatic view of a test apparatus showing a cold fluidsupply, a hot fluid supply, a mixed fluid outlet, a diffuser coupledbetween the supplies and the mixed fluid outlet, and decontaminationapparatus including a plurality of sensors coupled to the test apparatusto provide data.

DETAILED DESCRIPTION

As illustrated in FIG. 1, a decontamination apparatus 20 includes a heatexchange assembly 22, a fluid circulation network 24, and a mixing valve26. In the embodiment of FIG. 1, the heat exchange assembly includes aheater 28 for supplying heat to a fluid for increasing the temperatureof the fluid. To facilitate transportation of decontamination apparatus20, a support 32 is illustratively provided and is connected to fluidcirculation network 24 and heat exchange assembly 22. A plurality ofwheels 34 and a stand 36 are coupled to frame 32. Wheels 34 and stand 36cooperate with support 32, illustratively a frame 33, to support fluidcirculation network 24 and heat exchange assembly 22 in the positiondepicted in FIG. 1.

Circulation network 24 includes fluid supply inlet 40 to which a fluidsupply line 42 is couplable, fluid supply line 42 illustratively shownas a hose in FIG. 1. Fluid supply inlet 40 leads to a tee or otherjunction 44 at which fluid flowing through circulation network 24 isdivided—a portion of the fluid flows into a cold fluid line 46 and aportion flows into hot fluid line 48. Cold fluid line 46 extends fromjunction 44 to mixing valve 26, and is coupled to cold inlet 50 ofmixing valve 26. Hot fluid line 48 extends from junction 44, to heater28, and is coupled to mixing valve 26. As fluid flows through hot fluidline 48 adjacent heater 28, heat generated by heater 28 is applied tohot fluid line 48, increasing the temperature of the fluid flowingtherein. Hot fluid line 48 is coupled to hot inlet 52 of mixing valve26. Although FIG. 1 discloses junction 44 as dividing a single supplyline into the hot and cold fluid streams, it is within the scope of thisdisclosure to have separate hot and cold fluid supply lines supplyingrespective hot and cold fluids.

As illustrated in FIG. 1, mixing valve 26 includes a housing 54 in whichare mixed hot fluid flowing through hot inlet 52 and cold fluid flowingthrough cold inlet 50. Illustratively, mixed fluid temperature iscontrolled using a suitable thermostat and valve assembly, as is knownin the art. While reference is made to thermostatic mixing valves, it iswithin the scope of this disclosure to use other types of mixing valvesor systems as are known in the art, illustratively proportional mixingtechniques, pressure balancing valves, and the like. Mixed fluid flowsfrom housing 54 through mixed fluid outlet 56, and into mixed fluid line58. Mixed fluid line 58 leads to an emergency fixture depictedillustratively in FIG. 1 as an eyewash fixture 37.

As illustrated in FIG. 1, circulation network 24 has positioned thereina first diffuser 30 between the portion of hot fluid line 48 adjacentheater 28 and hot inlet 52 of mixing valve 26. Illustratively,circulation network 24 has positioned therein a second diffuser 30Abetween mixed fluid outlet 56 from mixing valve 26 and eyewash fluidinlet line 38. Eyewash fluid inlet line 38 includes a valve 39 thereinthat is operable by actuation of actuator 41. When a user actuatesactuator 41, opening valve 39, mixed fluid flows from mixed fluid outlet56 through mixed fluid line 58, toward eyewash fixture 37, througheyewash fluid line 38, and out eyewash outlets 43 of eyewash fixture 37.Refuse fluid is captured, at least in part, by basin 45 and is permittedto exit by way of drain 47. Illustratively, when a user actuatesactuator 41, a burner or other heating element (described more fullybelow) is ignited or otherwise powered to heat fluid flowing through hotfluid line 48. Optionally, decontamination apparatus 20 can be providedas a mobile unit.

As illustrated in FIG. 1, frame 33 includes side members 35 that arecoupled to heater 28. Side members 35 are coupled to a base 49illustratively including an axle tube 51 coupled to lower ends of sidemembers 35 and an axle (not shown) extending therethrough. Wheels 34 arecoupled to the axle to facilitate transport of decontamination apparatus20. Base 49 of frame 33 further includes a platform 53 having agenerally upwardly facing surface 55. Handles 57 are coupled to sideframe members 35 to further facilitate transport. Upper frame section 59is connected to side members 35, and illustratively is a generallyrectangular tubular section that extends outwardly from side members 35to provide additional support for heater 28. Also connected to frame 33are circulation network 24, mixing valve 26, fuel tank 112, andemergency (eyewash) fixture 37, whether directly connected to frame 33or indirectly through other parts of decontamination apparatus 20. Tomove decontamination apparatus 20, a user simply disconnects any fluidsupply line 42 connected to fluid supply inlet. The user positions afoot on axle tube 51 and pulls handles 57 in direction 61, lifting stand36 from engagement with the ground or floor. The user can then movedecontamination apparatus 20 by guiding handles 57 and rolling theapparatus using wheels 34.

Other fixtures are possible and are within the scope of this disclosure.For example, a decontamination fixture having one or more sprayers orwands (not shown) may be included. Such a sprayer or wand could includea trigger or other actuator that can be actuated by a user. The sprayeror wand may include a spray nozzle to create a desired pattern of spray.A user can use such a sprayer or wand to direct the flow of fluid fromthe wand in a pattern and/or a direction selected by a user.

As shown in FIG. 3, decontamination apparatus 320, described in furtherdetail below, is positioned on support 332. Support 332 is a platform333 upon which is positioned a heater 328, emergency fixture 510, andillustratively mixing valve 326. Platform 333 includes a generallyupwardly facing surface 335 sized to support heater 328 and emergencyfixture 510 thereon. Support members 337 extend from platform 333downwardly toward base 339. Support members 337 are illustrativelyspaced apart from each other and are positioned to receive the tines ofa fork truck, or other transportation or lifting device, therein topermit convenient transport of decontamination apparatus 320. To movedecontamination apparatus 320 from one location to another, any fluidsupply lines, drain lines, and fuel (or other power source) lines aredisconnected, and transportation or lifting device (not shown) ispositioned in spaces between support members 337 and platform 333 islifted so that support 332 and decontamination apparatus 320 areelevated above the ground or floor. Decontamination apparatus 320 isthen moved to the desired location.

While decontamination apparatus 20 of FIG. 1 and decontaminationapparatus 320 of FIG. 3 are illustrative examples configured forconvenient transport, using frame 20 of FIG. 1 and using a fork-truck orsimilar device to transport apparatus 320 of FIG. 3, it is understoodthat other configurations are within the scope of this disclosure. Otherportable, semi-portable, and non-portable configurations arecontemplated. A self-contained fluid supply vessel may be providedinstead of using water from a source such as a well, municipal watersupply, or other similar water source. Such an apparatus could betransported using a transportation device such as a truck, automobile,military vehicle, train, helicopter, or other mode of transportation. Adecontamination apparatus such as apparatus 320 of FIG. 3 could beaffixed using known methods to a structure in a building, for example,if portability of the apparatus is not desired.

In one configuration rather than having a burner, beating element 314 isprovided in an electric heater that enables a user to set thetemperature of hot water in the hot water supply to achieve and maintaina higher temperature than is possible with typical residential waterheater heating elements. In one exemplary configuration, a tubularheating element manufactured by Watlow Electric Manufacturing Company,12001 Lackland Road, St. Louis, Mo., USA 63146 is capable of maintainingwater at and above 180 degrees F. at typical flows for a sufficient timeto satisfy requirements for emergency applications. Such heatingelements are typically constructed to withstand higher temperatures andcurrents than standard residential heating elements. Further,thermostats associated with such heating elements are constructed topermit a user to select a temperature above about 185 degrees F.

Referring to FIG. 4, diffuser 30 includes a first conduit 60 and asecond conduit 62 surrounding, illustratively, a majority of firstconduit 60. First conduit 60 includes a first end 64 serving as an inletof fluid to diffuser 30, and an opposite second end 66. Second conduit62 includes a first end 74 serving as an outlet for fluid from diffuser30 and an opposite second end 76. As illustrated in FIG. 4, a cap 68 iscoupled to second end 76 to close second conduit 62. Cap 68 is coupledto second end 76 illustratively with solder applied around the perimeterof cap 68. It is understood that this diffuser design is illustrativeonly and that it is within the scope of this disclosure for diffusers tobe different in design.

In the illustrative embodiment, diffuser 30 includes a union 70 toassist in positioning first conduit 60 relative to second conduit 62 andto assist in directing or guiding the flow of fluid through diffuser 30.Union 70 is coupled to first ends 64, 74 of respective first and secondconduits 60, 62, illustratively with solder. Union 70 includes, at afirst end 71 thereof, a first opening 72 to receive first end 74 ofsecond conduit 62. Union 70 includes, at a second end 73 thereof, asecond opening 78 sized to receive first end 64 of first conduit 60.

Referring to FIG. 4, in operation, fluid enters diffuser 30 throughfirst end 64 of first conduit 60 adjacent second end 73 of union 70.Depending on the outlet configuration (described in more detail below),fluid generally flows in first direction 80 through first conduit 60from its first end 64 to its second end 66. Second end 66 is spacedapart from cap 68, permitting fluid to exit second end 66 of firstconduit 60 and reverse its direction to flow in a second direction 82,opposite first direction 80. First conduit 60 is positionedsubstantially within second conduit 62 so that when fluid exits secondend 66, the fluid remains within the volume defined by cap 68, secondconduit 62, and portions of union 70.

As shown in FIG. 4, union 70 includes, between its first and second ends71, 73, a reducing region 75 that necks down or reduces the diameter ofunion 70 from a diameter sized to receive the outside diameter of secondconduit 62 to a diameter sized to receive the outside diameter of firstconduit 60, thus forming a seal to prevent fluid from flowing fromsecond conduit 62 out of the fluid circulation network between firstconduit 60 and second end 73 of union 70. Union 70 includes an outlet 86formed between first end 71 thereof and reducing region 75.Illustratively, reducing region 75 is frustoconical in shape. An outlet86 surrounds an opening 88 formed in union 70 to permit fluid flowing indirection 82 to exit diffuser 30 and flow toward mixing valve 26.

As illustrated in FIGS. 4 and 5, optional spacers 89 are positionedbetween the conduits to discourage relative movement therebetween.Illustratively, spacers 89 are positioned adjacent second end 66 offirst conduit 60 and about the circumference of first conduit 60 tomaintain the relative position of first and second conduits 60, 62.Spacers 89 are illustratively constructed using crimped pieces of copperalloy tubing commonly used in the plumbing industry. If included,spacers 89 may, however, be constructed using any suitable material(s)and may have any shape sufficient to maintain the relative position ofconduits in a diffuser such as diffuser 30 and still permit adequateflow of fluid therethrough.

A first diffuser outlet configuration is depicted in diffuser 30 of FIG.4. A series of apertures 90, designated individually as 90A through 90K,are formed in first conduit 60 at various positions around first conduit60 and along its length. Apertures 90 A, B, and C are formed in,approximately, the first half 92 of the length of first conduit 60.Apertures 90 D through K are positioned in, approximately, the secondhalf 94 of the length of first conduit 60. Because apertures 90A through90K are positioned along the length of first conduit 60, portions offluid flowing through first conduit 60 exit through apertures 90 and mixwith fluid flowing outside of first conduit 60 and in second conduit 62.Illustratively, conduit 60 has an inside diameter of about 0.8 inchesand has an overall length C of about 29 inches, and conduit 62 has aninside diameter of about 1.25 inches and has an overall length A ofabout 24.25 inches. Second end 66 is spaced apart from cap 68 by adistance of B, illustratively about 0.75 inches. However, it isunderstood that other sizes for conduit 62 are within the scope of thisinvention.

As ‘fresh’ hot fluid (a second mass of fluid) that has been recentlyheated by heater 28 first flows through first conduit 60, the fresh hotfluid mixes with the previously stagnant fluid that was in first conduit60 and is in second conduit 62. Because apertures 90A-90J are providedalong the length of first conduit 60, some of the fresh hot fluid flowsthrough the first apertures 90 (for example 90A, 90B and 90C)encountered by the fluid flow without flowing all the way to second end66 of conduit 60, thus blending the fluid and rendering the blendedfluid a temperature between the temperature of the second mass of fluidand the stagnant fluid (a first mass of fluid) temperature. As morefresh hot fluid flows into first conduit 60, the blended temperaturegradually approaches that of the fresh hot fluid. By blending the fluidsas such, the fresh hot fluid does not reach mixing valve 26 at fulltemperature all at once, but rather reaches mixing valve 26 blended withpreviously stagnant fluid, thus providing the mixing valve a gradualincrease in fluid temperature instead of the more immediate increaseobtained without this blending.

First diffuser outlet configuration depicted in FIG. 4 illustratesapertures 90A through 90J formed as holes in first conduit 60 ongenerally opposite sides of the conduit, formed, for example, bydrilling through a first point along the length of first conduit 60 andpermitting the drilling device to penetrate through the opposite side ofthe conduit. It is understood, however, that any number of apertures 90Athrough 90J may be provided along the length and circumference ofconduit 60. In the illustrative embodiment, aperture 90A is positionedabout 13 inches from first end 64. Aperture 90B is positioned about 17inches from first end 64. Aperture 90C is positioned about 19 inchesfrom first end 64. Aperture 90D is positioned about 21 inches from firstend 64. Aperture 90E is positioned about 1 inch from aperture 90D.Apertures 90F through 90K are each positioned from the immediatelyadjacent aperture approximately the same distance as apertures 90D and90E are spaced apart. Illustratively, apertures 90A-J are holes drilledthrough conduit 60 so that a pair of holes, each 180 degrees around thecircumference of conduit 60 from the other, is at each position alongthe length of first conduit 60. Illustratively, apertures 90 are holesof 0.125 inch diameter drilled in conduit 60; however, apertures 90A-Jmay be of different sizes and shapes and each may be different from oneor more other apertures.

Although certain illustrative outlet configurations are disclosedherein, it is within the scope of this disclosure to use any suitableshape of aperture or combination of shapes. It is also within the scopeof this disclosure to space a wide range of sizes and numbers of suchapertures 90 apart from one another by various distances to achieve adesired mixing of fluid inside an internal conduit with the fluidoutside the internal conduit, and to maintain adequate flow through thediffuser. By way of example, additional outlet configurations aredepicted in FIGS. 8 through 13.

As shown in FIGS. 1 and 2, a portion of hot fluid line 48 passesadjacent heater 28 to receive heat generated by heater 28 and heat thefluid flowing through hot fluid line 48. Illustratively, hot fluid line48 is constructed of a copper alloy; however, use of other suitablematerials are within the scope of this disclosure. For example, steel,aluminum, brass, stainless steel, and other alloys or materials thathave desirable characteristics such as adequate strength, durability,corrosion resistance, and high heat transfer rates, and are suitable inparticular applications.

As shown in FIG. 2, illustrative heater 28 includes a heat exchangechamber 806 through which hot fluid line 48 passes with cool fluidentering through portion 810 of hot fluid line 48 and exiting throughportion 807. Illustrative heat exchange chamber 806 is sized to receiveburner 114 in its base region 122. Heat exchange chamber 806 isillustratively rectangular in shape and has a plurality of fins 124extending from a first side wall 126 to a second, opposite side wall128. As shown in FIG. 1, heater 28 includes a flue 130, the bottom 132of which is sized to approximate the size of top 134 of draught diverter805, the bottom 840 of which is coupled to the top 842 of heat exchangechamber 806. Excess heat and exhaust from the combustion process passesfrom heat exchange chamber 806 through flue 130 and exits through top136 of flue 130 to the atmosphere or other suitable destination. Asuitable heater 28 is available in the form of a water heater modelnumber 125 FX from Robert Bosch Corporation, Broadview, Ill., USA,although other heat exchangers are suitable, as are known in the art.

As shown in FIG. 1, heater 28 includes a fuel line 110 coupled to fueltank 112. The burner 114, shown in FIG. 2, is sized to fit within thebottom 844 of heat exchanger 806 and couples to a fuel valve 814 that isconfigured to control the flow of fuel from fuel line 110 to burner 114.Illustratively, fuel valve 814 is responsive to a controller system 118,shown and described in more detail below with reference to FIGS. 16 and17, or may have a manual control such as on/off switch 833, by whichfuel valve 814 opens upon certain conditions to provide fuel. If on/offswitch 833 is used, the switch may be accessed through opening 803 incover 801, which fits around heat exchange chamber 806, burner 114, andfuel valve 814. Fuel is supplied via ports 835 and 836 and,illustratively, controller system 118 and fuel valve 814 cooperate toopen fuel valve 814 and ignite fuel at burner 114 when actuator 41 isactuated by a user. It is within the scope of this disclosure for avariety of types of equipment to be used instead of or in addition tocontroller system 118 to determine whether, for example, power or fuelto heater 28 should be increased, or whether heater 28 should be startedor ignited. For example, a typical flow sensor could be incorporated todetect flow of fluid in hot fluid line 48, and when flow is detected inline 48, heater 28 is ignited. Further, a thermocouple to detect thetemperature of fluid flowing through hot fluid line 48 could likewise beincorporated. If fluid was flowing through hot fluid line 48 and thethermocouple detected a temperature below a set point, heater 28 couldbe started or otherwise turned up. It is understood that heater 28 isillustrative, and other heater configurations are within the scope ofthis disclosure.

As illustrated in the diagram of FIG. 16, cold fluid entering the heaterpasses through a valve assembly that allows gas to enter the burnersonly when fluid is flowing. A fluid flow sensor 728 signals computer 729to light burner 732, and the gas is ignited in the illustrativegas-fueled example by the pilot or spark ignition. Illustratively,burners 732 activate at a flow rate of 0.75 gallons per minute (GPM),with about 0.6 gpm continuous flow required to maintain burners 732 lit.Fluid is heated as it flows through heat exchanger 730, whichillustratively includes finned tube copper coils located adjacentburners 732. As the fluid flow rate changes, a governor (not shown)modulates the flow of gas to burners 732 to maintain a constanttemperature. The size of the flames and the energy used is thusproportional to the volume of hot fluid being moved through the system.The fluid temperature can be adjusted, illustratively from about 100° toabout 140° F., by adjusting gas proportioning valve 734.

Referring to FIGS. 14 and 15, a flame sensor 620 of heater 28 (shown inFIGS. 1 and 2) optionally may be positioned on pilot assembly 621 tosense when a flame 622 is present (FIG. 15), and to shut off the supplyof gas upon failure of flame 622 (FIG. 14). As shown in FIG. 17,optionally a flue gas sensor 713, a high temperature limiter 707, and anoverheat sensor 706 illustratively positioned in the flue, are coupledin series to an electronic control box 708, that controls a valve (notshown), the valve closing upon a signal from any one or more of thesesensors to stop the flow of gas. Flow sensor 728, shown in FIG. 16senses when the flow of fluid is stopped, similarly signaling to close avalve and shut off the flow of gas to the burners. Illustratively,heater 28 includes a push button piezo-electric pilot 624 shown in FIGS.14 and 15, and as 705 in FIG. 17, safety interlocked controls, and anillustrative copper heat exchanger 730 illustrated in FIG. 16. Further,illustratively heater 28 includes a slow ignition valve, high-efficiencylow-maintenance stainless steel burners 732, and filters (not shown) forthe pilot and burners to provide clogging protection.

An alternative embodiment of a diffuser 230 is illustrated in FIG. 5.Diffuser 230 is illustrated as a three-pass diffuser and includes firstconduit 232, a second conduit 234, and a third conduit 236. As shown inFIG. 5, first conduit 232 is positioned substantially within secondconduit 234, and second conduit 234 is positioned substantially withinthird conduit 236. A first union 238 cooperates with first, second, andthird conduits 232, 234, 236 to maintain the conduits in position. Firstunion 238 includes a first section 240 and a second section 242. Firstsection 240 includes a smaller diameter opening 244 sized to receivefirst conduit 232 therein. First section 240 includes a larger diameteropening 246 sized to receive the second conduit 234 therein. Firstsection 240 includes a reducing or neck down region 248 between openings244 and 246. Illustratively, reducing region 248 is frustoconical inshape. Second section 242 includes a smaller diameter opening 250 sizedto receive the second conduit 234. Second section 242 includes a largerdiameter opening 252 sized to receive the outside diameter of thirdconduit 236. Second section 242 includes a reducing or neck down region254 between openings 250 and 252. Illustratively, reducing region 254 isfrustoconical in shape. First section 240 and second section 242 offirst union 238 may be provided as two separate pieces or may optionallybe formed as a single first union part.

Diffuser 230 further includes a second union 256 spaced apart from firstunion 238. Second union 256 includes a larger diameter opening 258 sizedto receive an outlet end 260 of third conduit 236. Second union 256includes a smaller diameter opening 262 sized for coupling to a hotfluid line 264. Second union 256 includes a reducing or neck down region266 between openings 258, 262. Illustratively, reducing region 266 isfrustoconical in shape. End cap 226 has a side 227 sized to receive asecond end 239 of second conduit 324.

While the reducing regions described above are shown and described asbeing frustoconical in shape, it is within the scope of this disclosurefor one or more of the reducing regions to be other shapes. Further,although unions are described as being separate components from theconduits, it is within the scope of this disclosure to form diffusersfrom any number of pieces or to mold diffusers from a single piece. Oneof ordinary skill in the art will recognize that a wide variety offormation and/or assembly techniques may be implemented to make adiffuser.

First conduit 232 has a length F, illustratively about 53-54 inches.Second conduit 234 has a length E, illustratively about 50-51 inches.Third conduit 236 has a length D, illustratively about 48 inches.Illustratively, first, second, and third conduits 232, 234, 236 haveinside diameters of about 1, 1.5, and 2.5, inches respectively. Diffuser230 outlet configuration depicted in FIG. 5 illustrates apertures 290Athrough 290Q formed as holes in first conduit 232 and second conduit234, each hole illustratively having a second corresponding hole ongenerally opposite sides of the conduit, formed, for example, bydrilling through a first point along the length of the conduit andpermitting the drilling device to penetrate through the opposite side ofthe conduit. While two opposite holes are described for each ofapertures 290A through 290Q, such is illustrative, and any number ofholes of any shape are within the scope of this invention.

The sizes and spacing of the apertures 290 are described forillustrative purposes herein. As shown, illustrative apertures 290A are7/64 inch holes positioned in first conduit 232 about 12 inches fromfirst end 233 of first conduit 232, apertures 290B are 3/32 inch holespositioned about 24 inches from first end 233, apertures 290C are 5/64inch holes positioned about 36 inches from first end 233, apertures 290Dare 1/16 inch holes positioned about 48 inches from first end 233, andapertures 290E are 1/16 inch holes positioned about 2 inches from secondend 235.

Still referring to FIG. 5, illustrative apertures 290F are 9/16 inchholes positioned about 3.5 inches from first end 237 of second conduit234 or adjacent the reducing region 254 of the second section 242 offirst union 238. Illustrative apertures 290G are 9/16 inch holespositioned about 4.0 inches from first end 237 of second conduit 234,and are rotated 90 degrees around the circumference of second conduit234 relative to apertures 290F. Illustrative apertures 290H are 9/16inch holes positioned about 4.5 inches from first end 237 of secondconduit 234, and are rotated 90 degrees around the circumference ofsecond conduit 234 relative to apertures 290G. Illustrative apertures290I are 9/16 inch holes positioned about 5.0 inches from first end 237of second conduit 234, and are rotated 90 degrees around thecircumference of second conduit 234 relative to apertures 290H.Illustrative apertures 290J are 9/16 inch holes positioned about 5.5inches from first end 237 of second conduit 234, and are rotated 90degrees around the circumference of second conduit 234 relative toapertures 290I. Illustrative apertures 290K are 9/16 inch holespositioned about 6.0 inches from first end 237 of second conduit 234,and are rotated 90 degrees around the circumference of second conduit234 relative to apertures 290J. Illustrative apertures 290L are 9/16inch holes positioned about 6.5 inches from first end 237 of secondconduit 234, and are rotated 90 degrees around the circumference ofsecond conduit 234 relative to apertures 290K. Illustrative apertures290M are 9/16 inch holes positioned about 7.0 inches from first end 237of second conduit 234, and are rotated 90 degrees around thecircumference of second conduit 234 relative to apertures 290L.Illustrative apertures 290N are 3/32 inch holes positioned about 38.0inches from second end 239 of second conduit 234. Illustrative apertures290P are 3/32 inch holes positioned about 20.0 inches from second end239 of second conduit 234. Illustrative apertures 290Q are 3/32 inchholes positioned about 20.0 inches from second end 239 of second conduit234.

It is understood that fluid entering diffuser 230 at first end 233 offirst conduit 232 flows upward to end cap 226, then flows downwardbetween first conduit 232 and second conduit 234, down to aperture 290F,and then flows upward again between second conduit 234 and third conduit236, up to and out through hot fluid line 264. As fluid flows past eachof the apertures 290A through 290Q, newly heated fluid may flow throughthe apertures to mix with stagnant water that may already be in diffuser230.

An alternative heater embodiment, heater 328, is depicted in FIG. 3.Heater 328 is a standard “residential” water heater, illustratively a119 gallon water heater including a fuel line 310 coupled to fuel tank312 and burner 314. A fuel valve (not shown) may be coupled to fuel line310 to control flow of fuel to burner 314, and may be responsive to acontroller (not shown) to provide fuel when the controller senses thatadditional heat is to be supplied to increase the temperature of fluidstored in heater 328. Many fuels may be used, for example natural gas,propane, or other suitable fuel types. One of ordinary skill in the artwill appreciate that an electric water heater could be used forillustrative heater 328.

Heater 328 further includes a storage tank 302 in which fluid is storedthat enters storage tank 302 through a fluid inlet line 340. As shown inFIG. 3, a heat exchange region 321 includes an interface 323 adjacentburner 314. Interface 323 may take a number of forms, and may include acircuit through which hot combustion gases flow such as a coil, agenerally flat surface, or a heat sink extending into fluid stored instorage tank 320 to increase the surface area of interface 323 incontact with fluid in storage tank 320. If heater 328 is an electricheater, an electric element electrically coupled to an electric sourcecould heat the fluid in storage tank 320. Optionally, a filter 347 maybe provided, illustratively in fluid inlet line 340, to filter outparticulate matter. Filters may be provided elsewhere in the system,illustratively in cold fluid line 346.

As shown in FIG. 3, a mixing valve 326 receives hot fluid from hot fluidline 348 and cold fluid from cold fluid line 346. As with the embodimentdescribed with reference to FIG. 1, mixing valve 326 mixes hot and coldfluids and supplies tempered water through mixed fluid line 350. Adiffuser, illustratively diffuser 230 of FIG. 5, is coupled to hot fluidinlet line 348 and is between mixing valve 326 and the fluid outlet fromheater 328. An illustrative mixing valve is disclosed in U.S. Pat. No.5,647,531 assigned to Lawler Manufacturing Company, Inc. ofIndianapolis, Ind., the disclosure of which is hereby incorporated byreference herein. Other mixing valves of various configurations may beused depending on the specific requirements of the application in whichthe subject matter hereof is incorporated.

Still referring to FIG. 3, when a user actuates actuator 521, 526, or532, opening a valve 522, 534, mixed fluid flows from mixed fluid outletof the mixing valve and through mixed fluid line 350, toward fixture510.

As shown in FIGS. 3 and 6, a combination emergency fixture 510 isillustrated. Emergency fixture 510 includes a tempered fluid inlet 512receiving tempered water from a source such as the system shown in FIG.3. Emergency fixture 510 includes a fluid supply line 514 coupled tofluid inlet 512, the fluid supply line being coupled to an eyewashsupply line 516 and a emergency shower supply line 518. Eyewash supplyline 516 is coupled to an eyewash outlet fixture 520 so that, wheneyewash actuator 521 and valve 522 is actuated, fluid flows from fluidinlet 512 through fluid supply line 514, into eyewash supply line 516,and out eyewash outlet fixture 520. Basin 524 is provided to catch atleast part of the refuse fluid and divert the discarded fluid into adrain line 525. An optional foot actuator 526 is coupled with a link 528to valve 522 so that a user can actuate the eyewash by stepping on footactuator 526. Combination emergency fixture 510 further includes anemergency shower fixture 530 coupled to the emergency shower supply line518. A shower actuator 532 is operably coupled to a valve 534 so thatwhen a user actuates shower actuator 532, tempered fluid flows fromfluid inlet 512 through fluid supply line 514, into emergency showersupply line 518, and out emergency shower fixture outlet 536.

It is within the scope of this disclosure for heaters 28, 328 to bereplaced with another suitable heating device, for example a shell andtube heat exchanger—having a heating fluid flowing therethrough (whenaccess is had to such a heating fluid possessing sufficient heat toraise the temperature of supplied fluid by an acceptable amount).

Diffusers 30, 230 are illustratively constructed using a copper alloy.In these examples, copper is selected because of its high heat transferrate, and resultant ability to dissipate heat contained in fluid flowingthrough diffusers 30, 230. However, one of ordinary skill in the artwill recognize that many other materials could be used that providedesirable properties such as machinability, durability, corrosionresistance, compatibility with other system materials, cost, and thelike.

In a further illustrative embodiment represented in FIG. 7, a conduit410 is depicted. Conduit 410 may serve as the inner conduit of adiffuser, the outer conduit, or a conduit between the outer and innerconduit in a three (or more) pass diffuser. Conduit 410 includes aninternal passageway 412 and an external surface 414. As shown in FIG. 7,external surface 414 includes a plurality of fins 416. Fins 416 areactually shown as a single spiral fin created using an extrusion processin which a thick-walled, illustratively copper alloy, tube is extrudedto form fins 416 from surface 414. An integral finned surface 418 isthus formed on conduit 410. Fins 416 increase the surface area ofexternal surface 414 and thus increase heat transfer into adjacentmatter such as fluid flowing outside of conduit 410. It is within thescope of this disclosure to include a separate finned surface 418constructed from a different piece of material than conduit 410 andconnect separate finned surface 418 to conduit 410 to permit heattransfer during operation from conduit 410 into separate finned surface418. It is within the scope of this disclosure to form fins 416independently instead of as a single, spiral fin. Conduit 410 couldserve as an external conduit, middle conduit (such as in a three-passdiffuser configuration) or an inner conduit. A finned conduit may beused instead of or in addition to a conduit with plurality of apertures,or, alternatively, the finned conduit may be provided with one or moreapertures, to provide additional mixing.

Referring now to FIGS. 8 through 13, various aperture configurations aredepicted for the apertures provided in the diffusers. These apertureconfigurations are provided on the internal conduits—in other words,depending on the number of passes fluid makes through a particulardiffuse line, all conduits except for the outermost conduit may, or maynot, include such aperture configurations. Any number of passes may bemade through a diffuser, however consideration of physical, practical,and cost factors suggest that diminishing returns exist beyond a maximumnumber of passes. However, this maximum number of passes may varydepending on such factors as system size, pressure, and flow rate, forexample. Generally, a higher number of passes should improve mixingbetween a first mass of fluid and a second mass of fluid adjacent thefirst mass upon entry into the diffuser. Further, a higher number ofpasses should improve heat transfer between such a first and secondfluid mass, from the fluid mass(es) and to the diffuser material.

FIG. 8 shows a plurality of apertures 90 evenly spaced along the lengthof conduit 60. FIG. 13 similarly shows a plurality of apertures 690Athrough 690E. However, apertures 690A through 690 E are depicted as notevenly spaced. For example, Apertures 690D and 690E are more closelyspaced than apertures 690A and 690B, and illustratively the spacinggradually decreases from 690A to 690E. A combination arrangement isshown in FIG. 4, with spacing gradually decreasing in first half 92 fromaperture 90A to aperture 90D, and the spacing remaining essentiallyconsistent between apertures in second half 94, from aperture 90D toaperture 90K. Apertures 95-98 in FIGS. 9-12 depict a variety ofillustrative shapes including rhomboid, ovoid, rectangular, andparallelogram shapes. However, it is understood that these shapes areillustrative only, and that other shapes, including irregular shapes,may be included and are within the scope of this disclosure.Additionally, any shape aperture may be used with any aperture spacingto achieve the desired mixing effect of fluid in the conduit.

FIG. 8 illustrates substantially circular holes, FIG. 9 illustrates asubstantially diamond (rhomboid) aperture, FIG. 10 illustrates asubstantially oval aperture, FIG. 11 illustrates a substantiallyrectangular aperture, FIG. 12 illustrates an angularly-orientedparallelogram-shaped aperture, and FIG. 13 illustrates a series ofapertures positioned at points A, B, C, D, and E along conduit 660.

Diffusers 30, 230 may also serve as heat sinks. The heat sink is athermally conductive structure that has a mass per unit of linear lengthof net fluid flow greater than the average mass per unit of linearlength of net fluid flow in the overall fluid flow network.Illustratively, the heat sink comprises copper. In one exemplaryconfiguration, the heat sink surrounds a first fluid conduit such asconduits 60, 232 of FIGS. 4 and 5, so that fluid flowing from the firstfluid conduit subsequently flows through a passageway defined by orotherwise through the heat sink. Further, while the diffusersillustrated herein are used in conjunction with portable emergencyfixtures, it is understood that the diffusers may be used with anyfixture for which temperature control is desired. Such fixtures includefixed stationary emergency fixtures, as well as sinks, showers, and anyother fluid fixture. The diffusers illustrated herein may also be usedin combination with hot water heaters, for whatever purpose, wherein thediffuser would be installed in the hot water line exiting from the hotwater heater. Other applications for the diffusers are possible.

The following chart contains data from a test performed using a diffusersimilar to the diffuser shown in FIG. 3:

Example 1

TABLE 1 Temperature Temperature Temperature Pressure of (° F.) of (° F.)of (° F.) of hot water at Time Cold Water Hot Water Mixed Water mixingpoint 3:00:42 PM 43.4509 171.7 84.6336 1.92 3:00:52 PM 43.3573 171.92484.8198 3.02 3:01:02 PM 43.3417 172.67 85.6164 6.55 3:01:12 PM 43.4275173.252 144.085 6.40 3:01:22 PM 43.4119 173.739 165.607 7.14 3:01:32 PM43.4275 174.084 169.902 6.42 3:01:42 PM 43.4509 174.396 171.483 7.073:01:52 PM 43.5757 174.592 171.985 6.91 3:02:02 PM 44.0981 174.896172.683 6.65 3:02:12 PM 45.1031 175.031 172.92 6.81 3:02:22 PM 46.2003175.024 173.34 7.12 3:02:32 PM 47.0322 175.207 173.489 7.12 3:02:42 PM47.7779 175.274 173.638 7.11 3:02:52 PM 48.3911 175.301 173.807 6.983:03:02 PM 45.5001 175.288 173.699 3.03 3:03:12 PM 44.2462 175.031121.81 2.32 3:03:22 PM 44.1292 174.592 95.1776 1.99 3:03:32 PM 43.9032174.497 91.0316 2.85 3:03:42 PM 43.9655 174.166 89.2846 3.01 3:03:52 PM44.1994 173.936 88.4988 1.58 3:04:02 PM 43.7784 173.821 87.9795 2.063:04:13 PM 43.5133 173.631 87.8607 2.73 3:04:23 PM 43.3495 173.57787.6083 1.67 3:04:33 PM 43.2715 173.36 83.1573 1.27 3:04:43 PM 43.1544173.266 81.656 1.91 3:04:53 PM 43.131 173.184 81.2523 1.39 3:05:03 PM43.0842 173.089 81.1551 2.66 3:05:13 PM 43.0452 173.029 80.9755 2.323:05:23 PM 42.9437 172.981 80.9306 0.05 3:05:33 PM 42.9906 172.75881.1326 0.03 3:05:43 PM 43.014 172.649 81.3495 0.03 3:05:53 PM 43.014172.52 82.1269 0.03 3:07:30 PM 45.8493 170.537 84.7979 0.03 3:07:32 PM45.966 170.537 84.7979 0.03 3:07:35 PM 46.0516 170.496 84.783 0.033:11:16 PM 45.6476 164.755 89.4627 0.03 3:11:26 PM 45.7643 164.61889.3071 0.03 3:11:36 PM 45.7176 164.434 89.1515 0.03 3:11:46 PM 45.7487164.243 89.0329 0.03 3:11:56 PM 45.9277 165.308 97.7428 6.52 3:12:06 PM47.0629 166.746 148.545 6.84 3:12:16 PM 47.3194 168.571 159.367 6.983:12:26 PM 47.2727 170.29 162.992 6.92 3:12:36 PM 47.3349 170.752 165.435.59 3:12:46 PM 46.2389 170.847 159.882 2.24 3:12:56 PM 46.0678 170.989106.999 3.43 3:13:06 PM 46.06 171.111 99.4216 3.38 3:13:16 PM 45.8733171.478 97.6253 2.34 3:13:26 PM 45.492 171.762 93.4761 2.47 3:13:36 PM45.0872 172.068 92.192 2.40 3:13:46 PM 44.5108 172.244 91.8522 2.853:13:56 PM 44.1991 172.461 91.5567 1.63 3:14:06 PM 43.934 172.61691.2092 2.70 3:14:16 PM 43.8405 172.691 91.1279 3.16 3:14:26 PM 43.7859172.766 91.0466 1.84 3:14:36 PM 43.7079 172.874 88.8771 3.14 3:14:46 PM43.7157 172.942 88.5583 2.85 3:14:56 PM 43.6767 172.921 88.3432 2.493:15:06 PM 43.6303 172.981 88.343 2.31 3:15:16 PM 43.5835 172.893 88.5732.65 3:15:26 PM 43.5211 172.873 88.573 1.64 3:15:36 PM 43.4197 172.86688.5136 3.12 3:15:46 PM 43.3417 172.839 88.0759 2.40 3:15:56 PM 43.2559172.656 76.8887 2.40 3:16:06 PM 43.209 172.534 76.9037 1.41 3:16:16 PM43.2012 172.5 80.2271 0.03 3:16:26 PM 43.209 172.331 80.1597 1.913:16:36 PM 43.2246 172.737 91.7855 7.00 3:16:46 PM 43.2246 173.238157.181 7.02 3:16:56 PM 43.2246 173.672 168.195 6.79 3:17:06 PM 43.2402173.956 170.493 6.81 3:17:16 PM 43.2559 174.301 171.585 6.93 3:17:26 PM43.2793 174.423 172.222 6.69 3:17:37 PM 43.3105 174.653 172.859 6.983:17:47 PM 43.3963 174.72 171.266 0.03 3:17:57 PM 43.6069 174.639 170.880.03 3:18:07 PM 43.9804 174.581 170.149 0.03 3:18:17 PM 44.6039 173.552170.522 1.87 3:18:27 PM 44.1987 173.187 116.597 3.45 3:18:37 PM 44.1753173.816 105 4.21 3:18:47 PM 44.2299 173.776 107.761 6.24 3:18:57 PM44.2299 173.952 142.44 5.79 3:19:07 PM 44.1831 174.08 158.029 5.793:19:17 PM 44.261 174.33 160.143 5.79 3:19:27 PM 44.339 174.303 154.4555.66 3:19:37 PM 44.3623 174.249 150.432 5.59 3:19:47 PM 44.3857 174.445149.94 5.84 3:19:57 PM 44.5805 174.398 148.83 0.03 3:20:07 PM 44.6221174.299 118.859 0.03 3:20:17 PM 44.2714 174.218 71.4021 0.03 3:20:27 PM44.1389 173.541 61.8197 0.03 3:20:37 PM 43.9804 172.353 65.3808 0.033:20:47 PM 43.9596 172.823 75.4319 0.45 3:20:57 PM 43.8511 173.11281.5016 4.65 3:21:07 PM 43.8667 173.343 88.7164 5.76 3:21:17 PM 43.8511173.674 138.142 5.57 3:21:27 PM 43.8433 173.959 146.358 5.96 3:21:37 PM43.8667 174.182 149.282 5.31 3:21:47 PM 43.8979 174.5 150.273 5.763:21:57 PM 43.9758 174.561 150.717 6.08 3:22:07 PM 43.9836 174.466151.014 5.63 3:22:17 PM 44.0304 174.594 151.346 4.22 3:22:27 PM 44.0772174.635 139.776 3.73 3:22:37 PM 44.0694 174.703 124.316 4.40 3:22:47 PM44.0304 174.79 124.216 4.73 3:22:57 PM 43.9914 174.703 126.607 4.473:23:07 PM 43.9914 174.689 126.919 4.56 3:23:17 PM 44.007 174.689127.792 4.28 3:23:27 PM 44.0304 174.676 130.123 4.98 3:23:37 PM 44.007174.723 131.121 4.50 3:23:47 PM 44.0304 174.696 132.166 5.07 3:23:57 PM44.0227 174.729 134.944 5.15 3:24:07 PM 43.9838 174.675 135.331 0.033:24:17 PM 43.8045 174.587 107.9 0.03 3:24:27 PM 43.6485 174.181 55.06610.03 3:24:37 PM 43.5939 174.235 47.9435 1.58 3:24:47 PM 43.5159 172.55755.5128 2.60 3:24:57 PM 43.4613 172.855 74.6183 1.94 3:25:07 PM 43.4223173.207 74.5957 1.31 3:25:17 PM 43.3989 173.098 74.4224 2.68 3:25:27 PM43.3911 172.882 78.4307 4.91 3:25:37 PM 43.4067 173.173 110.219 5.203:25:47 PM 43.4613 173.491 129.762 5.08 3:25:57 PM 43.4691 173.64133.013 5.20 3:26:07 PM 43.5003 173.87 133.852 5.08 3:26:17 PM 43.5471174.127 134.282 5.31 3:26:27 PM 43.6173 174.093 134.627 5.25 3:26:37 PM43.5939 174.033 134.951 5.44 3:26:47 PM 43.5861 174.107 135.036 0.603:26:57 PM 43.5401 173.962 98.6244 0.03 3:27:07 PM 43.4387 173.8256.8212 0.03 3:27:17 PM 43.3997 173.482 48.0761 0.03 3:27:27 PM 43.3451173.313 45.628 0.03 3:27:38 PM 43.2593 173.164 47.3618 0.03 3:27:48 PM43.2359 171.741 55.3284 0.03 3:27:58 PM 43.2124 171.476 59.6308 0.033:28:08 PM 43.1968 171.32 56.2213 0.03 3:28:18 PM 43.1344 171.14448.1149 0.03 3:28:28 PM 43.111 170.981 44.8494 0.03 3:28:38 PM 43.0564170.927 44.0781 0.03 3:28:48 PM 43.0252 170.757 43.8598 0.03 3:28:58 PM42.994 170.52 44.4911 0.03 3:29:08 PM 42.955 170.18 49.4645 0.03 3:29:18PM 42.9471 169.895 50.7347 0.03 3:29:28 PM 42.9003 169.691 51.0674 0.033:29:38 PM 42.9342 169.374 51.2093 0.03 3:29:48 PM 42.8938 169.22951.1929 0.03 3:29:58 PM 42.9016 168.963 51.1233 4.77 3:30:08 PM 42.9407170.139 90.075 4.94 3:30:18 PM 42.9407 170.703 123.685 5.31 3:30:28 PM42.9641 171.347 129.39 5.37 3:30:38 PM 43.0187 172.012 131.364 4.603:30:48 PM 43.0655 172.52 130.601 4.84 3:30:58 PM 43.0967 172.947130.601 5.21 3:31:08 PM 43.1514 172.906 130.983 5.20 3:31:18 PM 43.1358172.798 131.315 4.88 3:31:28 PM 43.1748 173.17 131.647 4.61 3:31:38 PM43.206 173.698 131.704 5.07 3:31:48 PM 43.2372 174.064 131.739 4.943:31:58 PM 43.2684 174.287 131.986 4.51 3:32:08 PM 43.3152 174.402132.276 5.23 3:32:18 PM 43.323 174.442 132.445 5.08 3:32:28 PM 43.3698174.524 132.636 4.23 3:32:38 PM 43.4322 174.483 132.706 5.11 3:32:48 PM43.4406 174.515 132.663 4.55 3:32:58 PM 43.4874 174.488 132.536 4.583:33:08 PM 43.503 174.508 132.536 5.14 3:33:18 PM 43.5186 174.508132.472 4.33 3:33:28 PM 43.5498 174.535 124.097 4.83 3:33:38 PM 43.5654174.596 136.853 5.53 3:33:48 PM 43.5888 174.657 143.873 5.07 3:33:58 PM43.6512 174.623 146.047 5.39 3:34:08 PM 43.6512 174.664 146.339 5.773:34:18 PM 43.6902 174.731 146.443 5.84 3:34:28 PM 43.7447 174.657146.589 5.72 3:34:38 PM 43.7993 174.738 146.624 5.65 3:34:48 PM 43.8461174.779 148.618 5.48 3:34:58 PM 43.9007 174.846 152.621 5.61 3:35:08 PM43.9163 174.826 153.16 5.58 3:35:18 PM 43.9708 174.738 153.36 6.053:35:28 PM 44.002 174.813 153.395 5.26 3:35:38 PM 44.0569 174.818153.463 5.28 3:35:48 PM 44.1192 174.872 153.47 5.98 3:35:58 PM 44.1816174.859 153.504 5.84 3:36:08 PM 44.2544 174.895 153.514 4.46 3:36:18 PM44.2934 174.875 151.779 4.84 3:36:28 PM 44.309 174.712 139.422 3.033:36:38 PM 44.3012 174.679 116.732 2.69 3:36:48 PM 44.2778 174.374108.42 2.70 3:36:58 PM 44.2154 174.178 101.754 0.76 3:37:08 PM 44.1843174.023 99.4504 1.08 3:37:18 PM 44.1609 173.671 95.4277 1.91 3:37:29 PM44.1297 173.461 94.3308 0.03 3:37:39 PM 44.0362 173.386 88.8547 0.033:37:49 PM 43.927 172.953 75.2487 0.03 3:37:59 PM 43.8257 172.52 71.8610.03 3:38:09 PM 43.7399 172.255 70.7566 0.03 3:38:19 PM 43.7009 172.08670.1736 0.03 3:38:29 PM 43.6619 171.889 69.8857 0.03 3:38:39 PM 43.6235171.752 66.6978 0.03 3:38:49 PM 43.5377 171.508 53.2521 0.03 3:38:59 PM43.5221 171.379 48.2911 0.03 3:39:09 PM 43.5065 171.148 46.4735 0.033:39:19 PM 43.4909 171.107 45.6879 0.03 3:39:29 PM 43.4519 171.01245.1586 0.03 3:39:39 PM 43.3739 170.741 44.9873 0.03 3:39:49 PM 43.3115170.66 44.6913 0.03 3:39:59 PM 43.2647 170.361 44.6368 0.03 3:40:09 PM43.2413 170.252 44.5822 0.03 3:40:19 PM 43.2023 170.089 44.5433 0.033:40:29 PM 43.1867 169.695 47.2817 0.03 3:40:39 PM 43.1477 169.15249.6559 0.03 3:40:49 PM 43.1817 168.801 50.65 0.03 3:40:59 PM 43.1895168.474 50.7661 0.03 3:41:09 PM 43.1505 168.188 51.1221 0.03 3:41:19 PM43.1165 167.805 51.127 0.03 3:41:29 PM 43.1583 167.569 51.1453 0.033:41:39 PM 43.1506 166.683 51.1221 5.70 3:41:49 PM 43.1896 168.55693.6402 5.33 3:41:59 PM 43.2442 169.31 137.937 5.51 3:42:09 PM 43.252170.343 146.154 6.10 3:42:19 PM 43.3222 171.076 148.315 6.05 3:42:29 PM43.3768 171.93 149.619 6.08 3:42:39 PM 43.4002 171.869 150.679 5.983:42:49 PM 43.4782 171.883 151.517 5.71 3:42:59 PM 43.5484 172.622151.994 6.04 3:43:09 PM 43.6264 173.312 152.056 5.45 3:43:19 PM 43.681173.387 151.635 0.03 3:43:29 PM 43.5328 173.238 76.0342 0.03 3:43:39 PM43.4938 172.716 51.1144 0.03 3:43:49 PM 43.4626 172.628 46.7018 0.033:43:59 PM 43.2832 172.649 45.9164 0.03 3:44:09 PM 43.1896 170.69654.4813 0.03 3:44:19 PM 43.1194 170.316 63.2646 0.03 3:44:29 PM 43.0884170.621 62.9592 0.03 3:44:39 PM 43.0337 171.211 60.8798 0.03 3:44:49 PM43.0259 171.116 60.5047 0.03 3:44:59 PM 42.9713 170.98 57.6287 0.033:45:09 PM 42.8933 170.919 56.1526 0.03 3:45:19 PM 42.8152 170.66855.9295 0.03 3:45:29 PM 42.7528 170.315 55.7755 0.03 3:45:39 PM 42.7294170.01 54.5354 0.03 3:45:49 PM 42.7684 170.566 54.7897 6.72 3:45:59 PM42.7918 171.53 140.362 6.67 3:46:09 PM 42.8337 172.231 163.43 7.063:46:20 PM 42.8337 172.705 168.136 6.64 3:46:30 PM 42.8493 172.766167.121 0.03 3:46:40 PM 43.1146 172.664 166.42 0.03 3:46:50 PM 43.3019172.522 134.064 0.03 3:47:00 PM 43.2083 172.17 64.1372 0.03 3:47:10 PM43.5281 171.919 65.7372 0.03 3:47:20 PM 43.5281 171.817 76.383 0.033:47:30 PM 43.5437 171.614 83.1848 0.03 3:47:40 PM 43.5671 171.48584.8249 0.03 3:47:50 PM 43.5671 171.363 85.5247 0.03

FIG. 20 depicts a diagrammatic or schematic diagram of the test fromwhich the above data were derived. In the test represented by the dataof Table 1 and FIGS. 19A-G, and as schematically depicted in FIG. 20, acold water line 910 from cold water supply 911 was coupled to a mixedwater inlet 912, a hot water line 914 from hot water supply 913 wascoupled to mixed water inlet 912. A diffuser 916 was coupled to mixedwater inlet 912 so that hot and cold water flowed through mixed waterinlet 912 and into diffuser 916. A mixed water outlet 918 was coupled todiffuser 916 so that water flowing from the diffuser passed throughoutlet 918 toward a drain (not shown). Thermocouples 920, 922, 924, werecoupled to cold inlet, hot inlet, and mixed fluid outlet linesrespectively to measure the temperature of the water flowing througheach. A pressure sensor 926 was positioned in the hot water line tosense the pressure in the hot water. Thermocouples 920, 922, 924 andsensor 926 were coupled to computer 928 which recorded the data fromeach thermocouple, as depicted in Table 1 above. Valves 930 werepositioned in each of the water lines to shut off or throttle flow ofthe hot, cold, and/or mixed water as necessary.

To simulate different stagnant hot fluid line temperatures that might beencountered in different settings, a starting mixed water temperaturewas arrived at by adjusting the hot 930 b and cold 930 a valves until adesired temperature was reached. For example, FIG. 19A shows a startingmixed fluid temperature of about 85 degrees F. Once the desired startingtemperature for the mixed water was achieved, all flow wassimultaneously shut off. Then, the hot water valve 930 b was openedfull-open to simulate the hot water displacing the stagnant water in thehot water line. Mixed water temperature in the mixed water outlet linewas recorded via thermocouple 924 (shown in the fourth column). Cold andhot water temperatures were recorded via thermocouples 920 and 922 inthe cold and hot water lines respectively, those temperatures shown inthe second and third columns respectively. The time of day each readingwas made is indicated in the first column, each entry separated from theprior entry by ten seconds. The pressure, represented in the fifthcolumn, was recorded in the hot water line, is shown in pounds persquare inch gauge (psig), and serves to indicate when the hot water wasopened to the full-open position.

Thermocouple 920 was about 6 feet away from the point where cold inletline 910 connects to mixed inlet line 912, and thermocouple 922 wasabout 6 feet away from the point where hot inlet line 914 connects tomixed inlet line 912 (each distance of about 6 feet including about 2feet of rubber hose). Thermocouple 924 and sensor 926 were about 5 feetaway (about 3 feet of which was rubber hose) from the point wherediffuser 916 connects to mixed outlet line 918.

FIGS. 19A through G represent graphically certain data from Table 1.Data were taken at ten (10) second intervals. The mixed watertemperature is observed to increase to a local maximum in each of thegraphs depicted in FIGS. 19A through G. The starting temperature of themixed water was controlled by adjusting the hot valve while leaving thecold valve in the full-open position to achieve a desired starting mixedwater temperature. The gradual increase in mixed water temperature,compared to plug flow through a single pass of pipe resulting in anearly immediate jump to hot water of equal temperature with thetemperature of the hot water in the water heater tank, demonstrates theeffects of the diffuser.

Although this invention has been described and illustrated in detailwith reference to certain illustrative embodiments, variations andmodifications exist within the scope and spirit of the invention asdescribed and defined in the following claims.

The invention claimed is:
 1. An apparatus for conditioning thetemperature of flowing water, comprising: a source of hot water; a shellhaving an interior, an inlet and an outlet, the inlet receiving flowingwater from the source, said shell including a first walled flowpathwithin the interior, said flowpath receiving water from the inlet ofsaid shell, the wall of said flowpath at least partly separating saidflowpath from the remainder of the interior, the wall of the firstflowpath including a first plurality of apertures, said apertures beingspaced apart from one another along the first flowpath, each aperturepermitting the flow of water out of the first flowpath; and athermostatically controlled valve having a hot water inlet; wherein thewater flowing into said flowpath exits from said apertures into theremainder of the interior and flows out of the outlet of said shell andinto the hot water inlet.
 2. The apparatus of claim 1 wherein the waterexiting said apertures into the remainder of the interior is a secondflowpath, and said first flowpath and said second flow path are insubstantially opposite directions.
 3. The apparatus of claim 1 whereinwater flowing from at least two of said apertures bypasses a portion ofthe first flowpath.
 4. The apparatus of claim 1 wherein said firstwalled flowpath is cylindrical, said shell includes a cylindricalportion, and the second flowpath includes an annular portioncorresponding to the cylindrical portion.
 5. The apparatus of claim 1,which further comprises a decontamination fixture receiving water fromthe mixed flow outlet.
 6. The apparatus of claim 1 wherein said firstwalled flowpath is a tube.
 7. The apparatus of claim 1 wherein saidsource is a water heater.
 8. A method for conditioning the temperatureof flowing water, comprising: providing a mixing chamber defining aporous internal flowpath between inlet and outlet, and athermostatically controlled mixing valve having an inlet and an outlet;storing fluid in the mixing chamber; providing heated fluid to the inletof the mixing chamber; progressively mixing the stored fluid with theheated fluid through the porosity of the internal flowpath within themixing chamber; providing mixed fluid from the outlet of the mixingchamber to the inlet of the valve; providing fluid at a predeterminedtemperature from the outlet of the valve.
 9. The method of claim 8wherein the stored fluid is cooler than the heated fluid.
 10. The methodof claim 8 which further comprises delaying an increase in thetemperature of fluid from the outlet of the mixing chamber by saidprogressively mixing.
 11. The method of claim 8 wherein said providingheated fluid is from a water heater.
 12. The method of claim 8 whereinsaid providing includes an emergency wash fixture, and which furthercomprises providing fluid from the outlet of the valve to the emergencywash fixture.
 13. The method of claim 8 wherein the porous internal flowpath includes a plurality of through holes in a wall of a tube.
 14. Themethod of claim 8 wherein said progressively mixing includes flowingwater within mixing chamber in two substantially opposite directions.15. The method of claim 8 which further comprises delaying an increasein the temperature of fluid from the outlet of the mixing chamber bysaid mixing.